Chromium-free hydrogenation of hydroformylation mixtures

Abstract

The invention relates to a process for the preparation of alcohols by hydrogenation of aldehydes, in which use mixture comprising at least one aldehyde and at least one accompanying component is brought into contact, in the presence of hydrogen, with a heterogeneous catalyst, giving a product mixture which comprises at least the alcohol corresponding to the hydrogenated aldehyde, and at least one by-product, where the catalyst comprises a support material, and nickel and copper applied thereto. The invention also includes a chromium-free catalyst suitable for hydrogenating aldehyde mixtures with different chain lengths, in particular those which originate from different hydroformylations and can also comprise substances with C═C double bonds.

What is claimed is: 
     
       1. A process for the preparation of alcohols from aldehydes in a single catalytic hydrogenation reaction, comprising contacting a use mixture with a heterogeneous catalyst in the presence of hydrogen to produce a product mixture, wherein:
 a) said use mixture originates from a hydroformylation reaction and comprises a plurality of aldehydes with the same number, n, of carbon atoms, and corresponding alcohols and high boilers, where n is a natural number between three and eighteen; 
 b) said use mixture comprises the following components adding up to 100% by weight:
 total fraction of the aldehydes having nine carbon atoms: 15% to 65% by weight; 
 total fraction of the alcohols having nine carbon atoms: 20% to 65% by weight; 
 total fraction of acetals: 0.5% to 5.5% by weight; 
 total fraction of other hydrocarbons: 0% to 40% by weight; 
 water: 0% to 1% by weight; 
 
 c) said product mixture comprises at least an alcohol corresponding to the hydrogenated aldehyde, and at least one by-product; 
 d) said catalyst comprises a support material comprising aluminium oxide or silicon dioxide or a mixture of aluminium oxide and silicon dioxide, with nickel and copper applied thereto, and which, in activated form, comprises the following composition adding up to 100% by weight:
 support material: from 85% by weight to 95% by weight; 
 copper: from 5.3% by weight to 8.4% by weight; 
 nickel: from 2.2% by weight to 3.9% by weight; 
 chromium: less than 50 ppm by weight; 
 others: less than 1% by weight. 
 
 
     
     
       2. The process of  claim 1 , wherein the specific pore volume of the support material is between 0.5 ml/g to 0.9 ml/g, determined by the cyclohexane immersion method, and the specific surface area of the support material (BET surface area) is between 240 m 2 /g to 280 m 2 /g, determined by ISO method 9277. 
     
     
       3. The process of  claim 1 , wherein said process is carried out at a pressure of between 15*10 5  Pa and 25*10 5  Pa and at a temperature between 140° C. and 180° C., the pressure and temperature being selected such that use mixture and product mixture are present in a liquid phase. 
     
     
       4. The process of  claim 3 , wherein the hydrogen is present in a superstoichiometric amount, the concentration of the hydrogen being selected such that at least some of the hydrogen is present dissolved in the liquid phase. 
     
     
       5. The process of  claim 2 , wherein said process is carried out at a pressure of between 15*10 5  Pa and 25*10 5  Pa and at a temperature between 140° C. and 180° C., the pressure and temperature being selected such that use mixture and product mixture are present in a liquid phase. 
     
     
       6. The process of  claim 5 , wherein the hydrogen is present in a superstoichiometric amount, the concentration of the hydrogen being selected such that at least some of the hydrogen is present dissolved in the liquid phase. 
     
     
       7. The process of  claim 1 , wherein said catalyst comprises support material in an amount of from 88% by weight to 92% by weight. 
     
     
       8. The process of  claim 1 , wherein said catalyst comprises copper in an amount of from 6.5% by weight to 7.0% by weight. 
     
     
       9. The process of  claim 1 , wherein said catalyst comprises nickel in an amount of from 2.8% by weight to 3.3% by weight. 
     
     
       10. The process of  claim 1 , wherein said catalyst comprises less than 5 ppm by weight of chromium. 
     
     
       11. The process of  claim 1 , wherein the surface area of said support material is 240 m 2 /g to 280 m 2 /g as determined by ISO method 9277. 
     
     
       12. The process of  claim 7 , wherein said catalyst comprises copper in an amount of from 6.5% by weight to 7.0% by weight. 
     
     
       13. The process of  claim 7 , wherein said catalyst comprises nickel in an amount of from 2.8% by weight to 3.3% by weight. 
     
     
       14. The process of  claim 7 , wherein said catalyst comprises less than 5 ppm by weight of chromium. 
     
     
       15. The process of  claim 7 , wherein the surface area of said support material is 240 m 2 /g to 280 m 2 /g as determined by ISO method 9277. 
     
     
       16. The process of  claim 12 , wherein said catalyst comprises nickel in an amount of from 2.8% by weight to 3.3% by weight. 
     
     
       17. The process of  claim 12 , wherein said catalyst comprises less than 5 ppm by weight of chromium. 
     
     
       18. The process of  claim 12 , wherein the surface area of said support material is 240 m 2 /g to 280 m 2 /g as determined by ISO method 9277. 
     
     
       19. The process of  claim 17 , wherein said catalyst comprises less than 5 ppm by weight of chromium. 
     
     
       20. The process of  claim 17 , wherein the surface area of said support material is 240 m 2 /g to 280 m 2 /g as determined by ISO method 9277.